fix one off by one bug

wellen/src/vcd.rs

@@ -1213,7 +1213,9 @@ fn parse_body(
                         state = match parse_first_token(&first)? {
                             FirstTokenResult::Time(value) => {
                                 // check to see if this time value is already past the stop position
-                                if pos > stop_pos {
+                                // we subtract one to account for the fact that the current
+                                // character is a whitespace and thus not part of the time command
+                                if pos - 1 > stop_pos {
                                     // exit
                                     progress_report.report(pos, true);
                                     return Ok(());